1. Field of the Invention
This invention relates to a method for making condenser microphones.
2. Description of the Related Art
Much attention has been paid to semiconductor condenser microphones due to the advantages of small size, reduced weight, precisely controlled dimension and pattern, batch production, low cost, and easy integration with relevant electronic components.
Conventional methods for making a condenser microphone include a single-wafer process and a two-wafer process. In the two-wafer process, the diaphragm and the back plate are formed on separate silicon wafers, which are then bonded together. After bonding, the pair of the wafers is diced into individual capacitor devices for making condenser microphones. In the single-wafer process, after formation of the layered structures, the silicon wafer is also required to be diced into individual capacitor devices.
The aforesaid conventional methods are disadvantageous in that the individual capacitor devices thus formed are likely to be damaged due to the dicing operation, which results in a decrease in the production yield.